// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// THE POSSIBILITY OF SUCH DAMAGE.

package xyz.noark.asm;

/**
 * A reference to a field or a method.
 *
 * @author Remi Forax
 * @author Eric Bruneton
 */
public final class Handle {

	/**
	 * The kind of field or method designated by this Handle. Should be
	 * {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 * {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 * {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
	 * {@link Opcodes#H_INVOKESPECIAL}, {@link Opcodes#H_NEWINVOKESPECIAL} or
	 * {@link Opcodes#H_INVOKEINTERFACE}.
	 */
	private final int tag;

	/**
	 * The internal name of the class that owns the field or method designated
	 * by this handle.
	 */
	private final String owner;

	/** The name of the field or method designated by this handle. */
	private final String name;

	/** The descriptor of the field or method designated by this handle. */
	private final String descriptor;

	/** Whether the owner is an interface or not. */
	private final boolean isInterface;

	/**
	 * Constructs a new field or method handle.
	 *
	 * @param tag the kind of field or method designated by this Handle. Must be
	 *            {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 *            {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 *            {@link Opcodes#H_INVOKEVIRTUAL},
	 *            {@link Opcodes#H_INVOKESTATIC},
	 *            {@link Opcodes#H_INVOKESPECIAL},
	 *            {@link Opcodes#H_NEWINVOKESPECIAL} or
	 *            {@link Opcodes#H_INVOKEINTERFACE}.
	 * @param owner the internal name of the class that owns the field or method
	 *            designated by this handle.
	 * @param name the name of the field or method designated by this handle.
	 * @param descriptor the descriptor of the field or method designated by
	 *            this handle.
	 * @deprecated this constructor has been superseded by
	 *             {@link #Handle(int, String, String, String, boolean)}.
	 */
	@Deprecated
	public Handle(final int tag, final String owner, final String name, final String descriptor) {
		this(tag, owner, name, descriptor, tag == Opcodes.H_INVOKEINTERFACE);
	}

	/**
	 * Constructs a new field or method handle.
	 *
	 * @param tag the kind of field or method designated by this Handle. Must be
	 *            {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 *            {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 *            {@link Opcodes#H_INVOKEVIRTUAL},
	 *            {@link Opcodes#H_INVOKESTATIC},
	 *            {@link Opcodes#H_INVOKESPECIAL},
	 *            {@link Opcodes#H_NEWINVOKESPECIAL} or
	 *            {@link Opcodes#H_INVOKEINTERFACE}.
	 * @param owner the internal name of the class that owns the field or method
	 *            designated by this handle.
	 * @param name the name of the field or method designated by this handle.
	 * @param descriptor the descriptor of the field or method designated by
	 *            this handle.
	 * @param isInterface whether the owner is an interface or not.
	 */
	public Handle(final int tag, final String owner, final String name, final String descriptor, final boolean isInterface) {
		this.tag = tag;
		this.owner = owner;
		this.name = name;
		this.descriptor = descriptor;
		this.isInterface = isInterface;
	}

	/**
	 * Returns the kind of field or method designated by this handle.
	 *
	 * @return {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 *         {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 *         {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
	 *         {@link Opcodes#H_INVOKESPECIAL},
	 *         {@link Opcodes#H_NEWINVOKESPECIAL} or
	 *         {@link Opcodes#H_INVOKEINTERFACE}.
	 */
	public int getTag() {
		return tag;
	}

	/**
	 * Returns the internal name of the class that owns the field or method
	 * designated by this handle.
	 *
	 * @return the internal name of the class that owns the field or method
	 *         designated by this handle.
	 */
	public String getOwner() {
		return owner;
	}

	/**
	 * Returns the name of the field or method designated by this handle.
	 *
	 * @return the name of the field or method designated by this handle.
	 */
	public String getName() {
		return name;
	}

	/**
	 * Returns the descriptor of the field or method designated by this handle.
	 *
	 * @return the descriptor of the field or method designated by this handle.
	 */
	public String getDesc() {
		return descriptor;
	}

	/**
	 * Returns true if the owner of the field or method designated by this
	 * handle is an interface.
	 *
	 * @return true if the owner of the field or method designated by this
	 *         handle is an interface.
	 */
	public boolean isInterface() {
		return isInterface;
	}

	@Override
	public boolean equals(final Object object) {
		if (object == this) {
			return true;
		}
		if (!(object instanceof Handle)) {
			return false;
		}
		Handle handle = (Handle) object;
		return tag == handle.tag && isInterface == handle.isInterface && owner.equals(handle.owner) && name.equals(handle.name) && descriptor.equals(handle.descriptor);
	}

	@Override
	public int hashCode() {
		return tag + (isInterface ? 64 : 0) + owner.hashCode() * name.hashCode() * descriptor.hashCode();
	}

	/**
	 * Returns the textual representation of this handle. The textual
	 * representation is:
	 *
	 * <ul>
	 * <li>for a reference to a class: owner "." name descriptor " (" tag ")",
	 * <li>for a reference to an interface: owner "." name descriptor " (" tag "
	 * itf)".
	 * </ul>
	 */
	@Override
	public String toString() {
		return owner + '.' + name + descriptor + " (" + tag + (isInterface ? " itf" : "") + ')';
	}
}
